This invention relates to a catalytic combustion burner system comprising a catalytic combustion burner and constituting a development in catalytic combustion burners known to date. It also relates to a flask fitted with such a burner system.
Catalytic combustion burners used to date are made in porous material and have, on their upper part, a peripheral zone, for example ring shaped, which bears a catalyst and a central zone without a catalyst creating a vaporisation zone.
By way of example, the burners described in the documents EP 0 277 875 B1 and WO 99/63267 under the applicant's name can be quoted.
This type of burner equipped with a wick is generally placed on the neck of a flask containing the combustible composition, the wick being immersed in the said combustible composition.
The combustible composition carried by the wick penetrates via capillarity into the pores of the porous material of the burner.
A certain amount of this composition thus enters into the peripheral zone bearing the catalyst and is subjected therein to catalytic combustion which keeps this peripheral zone at a high temperature.
Another amount of this combustible composition passes through the central zone without a catalyst and is subjected to diffusion via vaporisation therein.
However, it is noted that this diffusion as far as the peripheral and central zones is not ensured in a constant manner whilst in use and that it depends, through experience, to a large extent on the amount of combustible composition in the flask.
This diffusion can also be modified, if need be, following a possible carbonising of the wick which could have created particles that could block some of the pores of the burner.
By experience it is accepted that diffusion, in order to observe a deodorization and a purification of the ambient air, is satisfactory when the consumption of combustible composition is regular and constant.
Now, if regular and constant values of consumption are actually reached with the current catalytic combustion burners, they are principally reached when the flask is about two-thirds filled with combustible composition.
On the other hand, below and above this two-thirds proportion, there is a large variation in the consumption of combustible composition.
When the flask is completely filled up with combustible composition, the supply of combustible composition to the burner is too great and could result in limiting the operating of the burner even to the point of stopping it.
On the contrary, when the flask is no more than a quarter filled with combustible composition, the wick, which is usually made from cotton, no longer ensures the diffusion, in satisfactory operating conditions, of the combustible composition in the burner. Low consumption is then observed.
In addition, when the burner is kept operating until the combustible composition is all used, the wick is modified via carbonisation. Repeated use in such circumstances can still accelerate the ageing of the burner.
It is therefore noted, in every case, whether the flask is insufficiently filled up or, on the contrary, whether it is completely filled up, that the consumption of combustible composition varies significantly and thus restricts the performance in terms of the quality of perfuming, disinfecting and destroying molecules and that a deterioration of the burner can occur.